1. Field of the Invention
The present invention relates to a vehicle detection apparatus for detecting vehicles traveling with their light turned on and to a light control apparatus utilizing the vehicle detection apparatus.
2. Description of the Related Art
Vehicle detection apparatuses have been known, which can detect vehicles traveling with their light turned on during the hours of darkness. This type of apparatuses include, for example, one which employs a technique for detecting headlamps or tail lamps of vehicles by processing images captured by a camera.
In processing a captured image, such a vehicle detection apparatus entails the necessity of preventing confusion between light spots originating from street lamps or neon signs, and light spots originating from vehicles. A technique for coping with this confusion is known as disclosed, for example, in Japanese Patent Application Laid-Open Publication No. 6-276524. According to this technique, if a pair of horizontally located bright regions (light spots) are detected first, and then if another bright region is detected below the pair of bright regions, the pair of bright regions is regarded as being a light spot originating from a vehicle.
However, the vehicle detection apparatus disclosed in the above literature raises a problem that light spots originating from street lamps or building neon signs could be regarded erroneously as being light spots originating from a preceding actual vehicle, when those lamps/signs are positioned in the captured images as if they are light spots from actual preceding vehicles. This results in erroneous detection of vehicles, if such a particular positional relationship between the street lamps or building neon signs and actual preceding vehicles happens in capturing forward images.